Lightning and thunders always left me wondering as a kid. I would always wonder how my elders could look at the sky and predict the rain fall. Thunders and lightning were always fearsome. But it was in the later stages that I realised the science behind it.
I know most of you would have had these questions. So why and how does a lightning strike?
Even before we start discussing about it. First let us know what causes lightning. In monsoon we often get to see lightning followed by a thunder sound. The flashes of lightning are extremely intense and bright. We are momentarily blinded by them. Light travels faster than sound. That is the reason we see lightning first followed by the roaring thunder sound. Some lightning goes zig-zag in the sky and then strikes the ground with immensely loud sound.
Well, then how does the lightning strike the earth?
Clouds are made up of number of small water droplets. Water cycle is the main reason for the formation of these water droplets. Thunders are caused by huge clouds. A cloud looks like black-blue carpet from the ground are the huge clouds which cause lightning. The strong conventional currents moves up and down between the clouds. These currents carry water droplets. The friction between air currents and water droplets hit each other to produce electrical signals. The lightning sometimes occur between the clouds, sometimes in the clouds and in rare cases occurs between clouds and earth.
The negative charges collected at the bottom part of cloud induces positive charges on the ground below. This is the main reason for electrical discharge on ground. The lightning then makes it way towards the ground. This flow is very fast. And it lasts for very smaller period. Thus the large amount of charges which flows in small period gives rise to lightning and thunder. The air molecules encountering this current path are heated to an extent that they emit light. And thus this path is seen as bright streak. As you know sound is produced due to vibrations. There is expansion of air in the path off lightning. Due to the expansion the air molecules vibrate. These sudden movements of molecules of air produce the thunder roar which you hear. Have you observed that this thunder continues for a small duration, than making one big bang? It is because of the echo of sound. There are other clouds in the sky which reflects the thunder sound. Thus the sound continuously for a moment.
What happens if the lightning hits the ground?
You will be knowing about the damages. There will be lot of destruction being caused to tall trees and buildings. Electronic gadgets are prone to be damaged if lightning strikes it.